The following projects will be investigated: a) The kinetic model of carbohydrate metabolism and the differentiating organism will be perturbed by uracil, Pi and combinations of these compounds and glucose. b) Cellular levels of critical amino acids and citric acid cycle intermediates will be determined, and characterization of alpha keto-glutarate dehydrogenase will be initiated. c) A kinetic model of the citric acid cycle will be constructed. BIBLIOGRAPHIC REFERENCES: Wright, Barbara E. and Killick, K.A.: Trehalose Metabolism During Sporulation of Dictyostelium discoideum Spores. American Society for Microbiology. Reprinted from Spores VI: 73-84 (1975). Park, David J.M.: Flux Induced Biochemical Differentiation. J. Theor. Biol. 54: 363-379 (1975).